As you may recall, Haren was traded to the Chicago Cubs for Carlos Marmol in November. That deal was then called off for reasons that were never officially stated. Presumably it was because Haren's physical raised some red flags, as noted by Danny Knobler of CBS Sports.

How Many Innings Will Dan Haren Throw In 2013?

Less Than 100101-150151-200More Than 200Submit Votevote to see results

How Many Innings Will Dan Haren Throw In 2013?

Less Than 100

8.5%

101-150

24.3%

151-200

53.1%

More Than 200

14.1%

Total votes: 827

Seeing that "pending physical" at the end of Rosenthal's report does make you take a step back, but if everything checks out with Haren, this could end up being a very good deal for the Nationals.

Prior to battling injuries in 2012, Haren was a workhorse for a long time in both the American League and National League. He pitched at least 216 innings every season from 2005 to 2011 and had an ERA under 4.00 in six of those seven seasons.

Even in a down year last season, Haren still threw 176.2 innings, struck out 142 and only walked 38. His ERA spiked to 4.33 thanks to a significant jump in his home-run rate, but he usually has such good command and control of his stuff, especially when healthy, that he can thrive in Nationals Park.

The Nationals will now boast a rotation that consists of Stephen Strasburg, who should have no innings restrictions, Jordan Zimmermann, Gio Gonzalez, Haren and Ross Detwiler. That has the potential to be the best rotation, top to bottom, in the National League.